Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.) Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.
NM-Mint - $0.30
Lightly Played - $0.20
Moderately Played - $0.20
Heavily Played - $0.20
Damaged - $0.20
NM-Mint Non English - $0.30
Lightly Played Non English - $0.20
Moderately Played Non English - $0.20
Heavily Played Non English - $0.20
Damaged Non English - $0.20